Wiring Of The Main Circuit - Mitsubishi Electric FR-A500 Instruction Manual

2.2.2

Wiring of the main circuit

(1) Wiring instructions
1) Crimping terminals with insulation sleeves are recommended for use with the power and motor cables.
2) Cut the protective bushes of the wiring cover when running the cables. (22K or less)
3) Power must not be applied to the output terminals (U, V, W) of the inverter. Otherwise the inverter will be
damaged.
4) After wiring, wire off-cuts must not be left in the inverter.
Wire off-cuts can cause an alarm, failure or malfunction. Always keep the inverter clean.
When drilling mounting holes in a control box etc., exercise care to prevent chips and other foreign
matter from entering the inverter.
5) Use cables of the recommended size for wiring to make the voltage drop 2% or less.
If the wiring distance is long between the inverter and motor, a main circuit cable voltage drop will cause
the motor torque to decrease especially at the output of a low frequency. (A selection example for the
wiring length of 20m (65.62 feet) is shown on page 19.)
6) The overall wiring length should be 500m (1640.40 feet) maximum.
Especially for long distance wiring, the overcurrent protection may be misactivated or the devices
connected to the output side may misoperate or become faulty under the influence of a charging current
due to the stray capacitance of the wiring. Therefore, the maximum overall wiring length should be as
indicated in the following table. (When two or more motors are connected to the inverter, the total wiring
length should be within the indicated value.)
Inverter Capacity
Non-low acoustic noise mode
Low acoustic noise mode
Overall wiring length (1.5K or more)
7) Connect only the recommended optional brake resistor between the terminals P and PR <+ and PR>.
These terminals must not be shorted.
8) Electromagnetic wave interference
The input/output (main circuit) of the inverter includes high frequency, which may interfere with the
communication devices (such as AM radios) used near the inverter. In this case, install the FR-BIF
optional radio noise filter (for use on the input side only) or FR-BSF01 or FR-BLF line noise filter to
minimize interference.
0.4K
300m (984.24 feet)
200m (656.16 feet)
500m
(1640.40 feet) maximum
300m
(984.24 feet)
300m
(984.24 feet)
300m (984.24 feet) + 300m (984.24 feet) = 600m (1968.48 feet)
15
INSTALLATION AND WIRING
0.75K 1.5K or more
500m (1640.40 feet) 500m (1640.40 feet)
300m (984.24 feet) 500m (1640.40 feet)
2